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// SPDX-License-Identifier: GPL-2.0
/*
* PWM Greybus driver.
*
* Copyright 2014 Google Inc.
* Copyright 2014 Linaro Ltd.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/pwm.h>
#include <linux/greybus.h>
#include "gbphy.h"
struct gb_pwm_chip {
struct gb_connection *connection;
u8 pwm_max; /* max pwm number */
struct pwm_chip chip;
struct pwm_chip *pwm;
};
#define pwm_chip_to_gb_pwm_chip(chip) \
container_of(chip, struct gb_pwm_chip, chip)
static int gb_pwm_count_operation(struct gb_pwm_chip *pwmc)
{
struct gb_pwm_count_response response;
int ret;
ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_PWM_COUNT,
NULL, 0, &response, sizeof(response));
if (ret)
return ret;
pwmc->pwm_max = response.count;
return 0;
}
static int gb_pwm_activate_operation(struct gb_pwm_chip *pwmc,
u8 which)
{
struct gb_pwm_activate_request request;
struct gbphy_device *gbphy_dev;
int ret;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
ret = gbphy_runtime_get_sync(gbphy_dev);
if (ret)
return ret;
ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ACTIVATE,
&request, sizeof(request), NULL, 0);
gbphy_runtime_put_autosuspend(gbphy_dev);
return ret;
}
static int gb_pwm_deactivate_operation(struct gb_pwm_chip *pwmc,
u8 which)
{
struct gb_pwm_deactivate_request request;
struct gbphy_device *gbphy_dev;
int ret;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
ret = gbphy_runtime_get_sync(gbphy_dev);
if (ret)
return ret;
ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DEACTIVATE,
&request, sizeof(request), NULL, 0);
gbphy_runtime_put_autosuspend(gbphy_dev);
return ret;
}
static int gb_pwm_config_operation(struct gb_pwm_chip *pwmc,
u8 which, u32 duty, u32 period)
{
struct gb_pwm_config_request request;
struct gbphy_device *gbphy_dev;
int ret;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
request.duty = cpu_to_le32(duty);
request.period = cpu_to_le32(period);
gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
ret = gbphy_runtime_get_sync(gbphy_dev);
if (ret)
return ret;
ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_CONFIG,
&request, sizeof(request), NULL, 0);
gbphy_runtime_put_autosuspend(gbphy_dev);
return ret;
}
static int gb_pwm_set_polarity_operation(struct gb_pwm_chip *pwmc,
u8 which, u8 polarity)
{
struct gb_pwm_polarity_request request;
struct gbphy_device *gbphy_dev;
int ret;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
request.polarity = polarity;
gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
ret = gbphy_runtime_get_sync(gbphy_dev);
if (ret)
return ret;
ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_POLARITY,
&request, sizeof(request), NULL, 0);
gbphy_runtime_put_autosuspend(gbphy_dev);
return ret;
}
static int gb_pwm_enable_operation(struct gb_pwm_chip *pwmc,
u8 which)
{
struct gb_pwm_enable_request request;
struct gbphy_device *gbphy_dev;
int ret;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
ret = gbphy_runtime_get_sync(gbphy_dev);
if (ret)
return ret;
ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ENABLE,
&request, sizeof(request), NULL, 0);
if (ret)
gbphy_runtime_put_autosuspend(gbphy_dev);
return ret;
}
static int gb_pwm_disable_operation(struct gb_pwm_chip *pwmc,
u8 which)
{
struct gb_pwm_disable_request request;
struct gbphy_device *gbphy_dev;
int ret;
if (which > pwmc->pwm_max)
return -EINVAL;
request.which = which;
ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DISABLE,
&request, sizeof(request), NULL, 0);
gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
gbphy_runtime_put_autosuspend(gbphy_dev);
return ret;
}
static int gb_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
return gb_pwm_activate_operation(pwmc, pwm->hwpwm);
};
static void gb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
if (pwm_is_enabled(pwm))
dev_warn(chip->dev, "freeing PWM device without disabling\n");
gb_pwm_deactivate_operation(pwmc, pwm->hwpwm);
}
static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
int err;
bool enabled = pwm->state.enabled;
u64 period = state->period;
u64 duty_cycle = state->duty_cycle;
struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
/* Set polarity */
if (state->polarity != pwm->state.polarity) {
if (enabled) {
gb_pwm_disable_operation(pwmc, pwm->hwpwm);
enabled = false;
}
err = gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, state->polarity);
if (err)
return err;
}
if (!state->enabled) {
if (enabled)
gb_pwm_disable_operation(pwmc, pwm->hwpwm);
return 0;
}
/*
* Set period and duty cycle
*
* PWM privodes 64-bit period and duty_cycle, but greybus only accepts
* 32-bit, so their values have to be limited to U32_MAX.
*/
if (period > U32_MAX)
period = U32_MAX;
if (duty_cycle > period)
duty_cycle = period;
err = gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_cycle, period);
if (err)
return err;
/* enable/disable */
if (!enabled)
return gb_pwm_enable_operation(pwmc, pwm->hwpwm);
return 0;
}
static const struct pwm_ops gb_pwm_ops = {
.request = gb_pwm_request,
.free = gb_pwm_free,
.apply = gb_pwm_apply,
.owner = THIS_MODULE,
};
static int gb_pwm_probe(struct gbphy_device *gbphy_dev,
const struct gbphy_device_id *id)
{
struct gb_connection *connection;
struct gb_pwm_chip *pwmc;
struct pwm_chip *pwm;
int ret;
pwmc = kzalloc(sizeof(*pwmc), GFP_KERNEL);
if (!pwmc)
return -ENOMEM;
connection = gb_connection_create(gbphy_dev->bundle,
le16_to_cpu(gbphy_dev->cport_desc->id),
NULL);
if (IS_ERR(connection)) {
ret = PTR_ERR(connection);
goto exit_pwmc_free;
}
pwmc->connection = connection;
gb_connection_set_data(connection, pwmc);
gb_gbphy_set_data(gbphy_dev, pwmc);
ret = gb_connection_enable(connection);
if (ret)
goto exit_connection_destroy;
/* Query number of pwms present */
ret = gb_pwm_count_operation(pwmc);
if (ret)
goto exit_connection_disable;
pwm = &pwmc->chip;
pwm->dev = &gbphy_dev->dev;
pwm->ops = &gb_pwm_ops;
pwm->npwm = pwmc->pwm_max + 1;
ret = pwmchip_add(pwm);
if (ret) {
dev_err(&gbphy_dev->dev,
"failed to register PWM: %d\n", ret);
goto exit_connection_disable;
}
gbphy_runtime_put_autosuspend(gbphy_dev);
return 0;
exit_connection_disable:
gb_connection_disable(connection);
exit_connection_destroy:
gb_connection_destroy(connection);
exit_pwmc_free:
kfree(pwmc);
return ret;
}
static void gb_pwm_remove(struct gbphy_device *gbphy_dev)
{
struct gb_pwm_chip *pwmc = gb_gbphy_get_data(gbphy_dev);
struct gb_connection *connection = pwmc->connection;
int ret;
ret = gbphy_runtime_get_sync(gbphy_dev);
if (ret)
gbphy_runtime_get_noresume(gbphy_dev);
pwmchip_remove(&pwmc->chip);
gb_connection_disable(connection);
gb_connection_destroy(connection);
kfree(pwmc);
}
static const struct gbphy_device_id gb_pwm_id_table[] = {
{ GBPHY_PROTOCOL(GREYBUS_PROTOCOL_PWM) },
{ },
};
MODULE_DEVICE_TABLE(gbphy, gb_pwm_id_table);
static struct gbphy_driver pwm_driver = {
.name = "pwm",
.probe = gb_pwm_probe,
.remove = gb_pwm_remove,
.id_table = gb_pwm_id_table,
};
module_gbphy_driver(pwm_driver);
MODULE_LICENSE("GPL v2");
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